Over the weekend I met Tara, the trainer my sister is taking lessons with. She was one of Clinton Anderson's apprentices, you might have seen her on the show. She was working with my sister's horse under saddle, and another horse on the ground. With that one she just happened to do the one thing I could NOT figure out how to do, that's been bothering me lately. I want to be able to bring the hindquarters toward me, like the reverse of yielding away. And she was doing it! So I asked how and showed us. She would lead the horse along the fence, stop his forward movement at his head, and tap her stick/whip at his flank. This horse knew it well enough that she only had to tap the air, but she said that to begin with you have to tap them. With rhythm, that's very important. The horse can't swing the hindquarters away, can't go forward or back, so eventually tries doing the only thing he can, swinging the flank toward you. Then it can be worked into side-passing toward you.
I tried it with Tonka yesterday and it was so cool! It took him a few minutes to figure out, and he was better on one side than the other, but he did it! Even side-passed a few steps toward me. I'm trying to think of a cue to differentiate it from moving him away, so I added the voice-cue "hip." Also, when I move him away I move or lean toward him, but when I wan't him to move toward me I don't, so that should help to differentiate the two cues. I can't wait to work with him more on it.